Why are my corals growing pale & receding?

[Aprod]

My tank has been really struggling over the last month or so and has not improved. Could use a hand.

Red Sea Reefer 250, Reefmat roller filtration, Nyos Skimmer, Radion XR15 Blue's x2

Parameters:
Alkalinity: 8.5 (Trident)
Calcium: 400 (Trident)
Mag: 1886 (Trident)
Nitrate: 6.7 (Hannah Checker)
Phosphate: 0.03 (Hannah Checker)
Temp: 78 degrees
Ph: 8.1 ~ 8.2
Salinity: 35ppt (1.026 sg)

No major changes or additions to anything that I have done. The tank sucks up Alkalinity and Calcium, but I am not even sure where it's going since it appears none of my sps is growing besides my Monti's and there is little coralline algae. Aside from Monti's, all other SPS coral looks sickly, pale and receded polyps; however, none have yet to succumb to RTN/ STN/ Tissue Loss from what i have seen. I have an ICP test in the works, but from what I can see, most of my major parameters look to be in ideal condition and stable.

I just rented a PAR meter today and the average reading is ~85 on floor, 150 lower tank, 200 highest points. I am planning to raise this over 30 days to get ~150 floor, 200 lower tank, and ~250 highest points over the next thirty days of acclimation. Although the Par could be higher, I find it hard to believe that it would be the cause of all these issues.

Does anyone have a clue what is going on?? Pictures:

Trumpet Coral losing flesh:

Blue Stylophora super pale and polyps rececded:

Goniopora shrunken, skeleton exposed at top:

Corals in the center seem to be doing fine, but no growth:

Apex:

 

[brandon429]

first cpr move is drop your light levels away from where they're at, don't chase a high par until things restore once you find the variables causing them to retract. going solely off that bleaching noted the lights need reduced a while and hardly any white ran

it needs far less white spectrum and about -20% less intensity for a few weeks until you figure out the issue. light overpower is driving that, drop it like clouds over a reef to buy you time. this is a good mode because even healthy reef tanks won't die if you reduce ~20% overall power for a couple weeks then ramp it back.

 

[Aprod]

first cpr move is drop your light levels away from where they're at, don't chase a high par until things restore once you find the variables causing them to retract. going solely off that bleaching noted the lights need reduced a while and hardly any white ran

it needs far less white spectrum and about -20% less intensity for a few weeks until you figure out the issue. light overpower is driving that, drop it like clouds over a reef to buy you time. this is a good mode because even healthy reef tanks won't die if you reduce ~20% overall power for a couple weeks then ramp it back.

Thanks for the advice and good points. I will dial it back until things start to perk up. Appreciate it!

 

[Lavey29]

Your magnesium is extremely high. This also messes up your alk and cal consumption. It's the buffer for those. Yes slowly raise par over 30 days.

 

[acrojunkie]

Your magnesium is extremely high. This also messes up your alk and cal consumption. It's the buffer for those. Yes slowly raise par over 30 days.

I agree and believe the Mg seems very high which is affectingt the Alk and Ca consumption.